Thanks for planning to put the mower and babies back where mom last saw them - hopefully she'll reunite with them today, soon. She normally sleeps during the day though, so if she was scared away this morning she may stay up all day fretting about her babies so it's hard to say what will happen tonight - but if that area can be kept quiet after the mower is put back hopefully she'll be with them by tomorrow morning....
If your birds were full grown, it is very unlikely that the skunk killed them. Skunks are generally nocturnal so if you are having daytime losses it is likely a different culprit. I would worry about chicks, because everyone 'out there' wants to eat them. If your birds - whatever their size - are locked up at night, the nocturnal preds will be out of luck.
One article I read said that up to 70% of a skunk's diet consists of insects considered harmful to humans, including black widow spiders and scorpions.
This is a real digression from the topic at hand, but I thought a nevertheless interesting para from one article - I had not heard this before: "Having adapted well to neighborhoods, it's not uncommon to find skunks and domestic cats dining peacefully together. There have been cases of skunks entering homes through pet doors, dining with the family cat and finding a quiet closet or empty bed to spend the night. As long as the skunk does not feel threatened, it won't spray."
Keep us posted!
JJ